1. Field of the Invention
This invention relates to a control system for an engine of a watercraft.
2. Description of the Related Art
Personal watercraft have become very popular in recent years. This type of watercraft is quite sporting in nature and carries one or more riders. A hull of the personal watercraft commonly defines a rider""s area above an engine compartment. An internal combustion engine powers a jet propulsion unit that propels the watercraft by discharging water rearward. The engine lies within the engine compartment in front of a tunnel, which is formed on an underside of the hull. The jet propulsion unit is placed within the tunnel and includes an impeller that is driven by the engine.
A deflector or steering nozzle is mounted on a rear end of the jet propulsion unit for steering the watercraft. A steering mast with a handlebar is linked with the deflector through a linkage. The steering mast extends upwardly in front of the rider""s area. The rider remotely steers the watercraft using the handlebar.
The engine typically includes at least one throttle valve disposed in an air intake passage of the engine. The throttle valve regulates the amount of air supplied to the engine. Typically, as the amount of air increases, the engine output also increases. A throttle lever or control is attached to the handlebar and is linked with the throttle valve(s) usually through a throttle linkage and cable. The rider thus can control the throttle valve remotely by operating the throttle lever on the handlebar. In this manner, engine speed is typically controlled.
Disclosed is an engine control for a watercraft in which the watercraft has an engine having an air intake regulator that is movable through a first range of positions including an idle position and a fully open position. There is preferably a remotely located engine speed control operator movable between a first position and a second position that is coupled to the air intake regulator.
The engine may further have a controller coupled to the air intake regulator to at least selectively control the air intake regulator. The controller is preferably configured to provide a first mode of engine operation in which movement of the engine speed control operator between the first and second positions causes the air intake regulator to move through the first range of opening positions from the idle position to the fully open position. The controller may further be configured to provide at least a second mode of engine operation in which movement of the engine speed control operator causes the air intake regulator to move through a second range of opening positions that is less than the first range of opening positions.
The controller may be in communication with a modality selector that is selectable between at least two states corresponding to the at least two modes of engine operation provided by the controller. The modality selector may be configured to output a modality signal to the controller that is indicative of the desired mode of engine operation, and the controller correspondingly controls the engine in response to the signal received from the modality selector.
In accordance with another embodiment of the invention, a watercraft has an internal combustion engine that drives a jet propulsion unit. The watercraft further has an engine output control system to restrict the quantity of air that is taken in by the engine, and a switching means for switching the engine output control between an air-restricting state and an unrestricting state. When the output control is switched to the air-restricting state, the maximum output of the engine is limited.
In accordance with another aspect of the present invention, a method is provided for controlling the air intake of an internal combustion engine between at least a first and second operation mode. The engine preferably has an air intake regulator operable through a first range of motion and a remote actuator operable through a first range of motion corresponding with the first range of motion of the air intake regulator. Preferably, a change in a desired operation mode from the first operation mode to a second operation mode is detected and the air intake regulator is varied such that the air intake regulator is operable through a second range of motion that is less than the first range of motion.
Further features and advantages of the present invention will become apparent to those of skill in the art in view of the detailed description of preferred embodiments which follows, when considered together with the attached drawings and claims.